When to grind valves?

[J Vernon Bailey]

Due to a failed fan clutch, I overheated my 93 6.5TD. It has 150,000 miles with no problems except throttle position sensor, so I plan to do a tear down and replace timing chain, water pump, glow plugs and injectors alomg with fan clutch and fan. I am wondering about what is the usual service life for the valves? Should I plan to have a valve grind doen also? I live in the Bryan, Texas area but not for long so I am going to have to search for a trustworthy shop. I do not plan on any heavy towing so do not intend to add the cooling mods.

Comments?
Thank You
Vernon
1993 K2500HD 6.5TD POT
(Plain Old Truck)

[Peter J. Bierman]

Normaly the valves and seats should live as long as your engine.
Only when problems occur like bad compression or when your heads are pulled for other repairs a valve job is done.
When the heads are off, mostly a light lap will do. Grinding is to be done when valve or seat are replaced.

Peter

[grape]

in the performance industry, the term "lap" as in with some sort of lapping compound is a huge "no no". This leaves trenches where the grit in the compound has ground the face of the valve and the seat. If an engine builder says he's gonna lap your valves........tell him to lap his own, and get the hell out of there.

[tom.mcinerney]

Might want to do a compression check before teardown; avoid headwork if not symptomatic. The heads sometimes develop small cracks thru valve seats when overheated....

[cruzer]

Do a compression check to see if there are any irregularities from cyl to cyl.Usually within 10%
is OK. Then do a cylinder leak down test to determine how/where suspect cylinders are leaking. Instead of cyl leak down test you can do wet and dry compression test,it will give you a general direction to go. Cyl leak down will tell you whats wrong.